Casing-head structure



May 28, 1940. F. CYPHER CASING-HEAD STRUCTURE Filed July 24, 1939 2 Sheets-Sheet 1 I l I. I I I ,FIG. 3

INVENTOR flue/1 E CYPHER KfZ/MJ.

ATTORNEY y 8, 1940. I H. F. CYPHER 2,202,192

CASING-HEAD smucwuaa Filed July 24, 1939 2 Sheets-Sheet 2 INVENTOR HUGH F CYPHR Fla. 2

ATTORNEY Patented May 28, 1940 v UNITED ,STATES PATENT 'oFrrce-Y' CASING-HEAD STRUCTURE Hugh F. Cypher, Berger, Tex., assignor of onehalf to Kenneth M. Axelrod, Berger, Tex.

Application July 24, 1939, Serial No. 286,077

' A 5 Claims. (Cl. 166-15) I This invention relates to casing-head structures for use in oil and gas wells, and relates particularly to an improved device used in oil and gas well casing heads and commonly termed a lubricator.

Lubricators are-commonly used in connection with the drillingof wells by means of cable tools, particularly at the stage of drilling when the well is. being completed while gas or oil under relatively high pressure is present in the well bore or casing. The lubricators are employed to permit the running of strings of tools into and out of the well without interference by the high pressure gas, and consist generally of an elongated chamber of sufiicient length to accommodate'the usual string of drilling tools, and'provided with a valve means at its lower end where by the too-lsmay be dropped into the well and operated therein afterthe pressure in the chamber has been equalized withthat. in the well. Similarly, the lubricator provides means .whereby the tools may be withdrawn from the-well, without interference from the gas andoilin the well, and without danger of, incurring blowouts during such operations.

Heretofore, lubricatorsof the general class described have been placed in the, derrick above .the mouth of the well and connected to the top of the casing. Such constructions have very definite disadvantages among which are, that the lubricator is limited in length to approximately one-half the height of the derrick in order to allow room in the derrick for insertion and withdrawal of strings of tools of that length 3) from the top of the lubricator. Frequently strings of tools of greater length are required, and especially when fishing jobs are required. In such a case the lubricator must belong enough to accommodate two strings of tools and obviously the conventional lubricator cannot be used. Also conventional lubricators, must be set of the nipple l.

nent part of the well head equipment, being I positioned within the well casing, below the top of the well, and which is safe and simple in operation, and adapted for use with strings of tools of any desired length.

Other objects and advantages of this'invention will be apparent from the following detailed description when read in'conjunction with the accompanying drawings which illustrate a preferred form of construction of the device of this invention.

In the drawings: I

Fig. 1 is a sectional view of the top of a well casing showing the casing-head structure of this invention positioned therein.

Fig. 2 is a side elevation of the lubricator structure. I

Fig. 3 is a sectional elevation of the lower end of the lubricat'o'r showing the valve details. 7

Fig. 4 is a detail of the 'lubricator valve i'n plan View, and I I Figs. 5 and 6 are elevation and plan views, respectively, of the valve operating apparatus.

Referring to the drawings, and Fig. 1 in particular, there is shown the usual well casing l extending from the top of a well above the floor 2 of a derrick, and provided at its upper end with a flanged head 3. The lubricator of this invention consisting 'generally of an elongated tubular chamber-5, extends into the bore of casing l and isprovided with a cover plate 6 which bolts to the upper face of 'flanged head 3. A nipple I connects to the upper end of chamber 5 through "cover plateli'and on topof nipple l is mounted a conventional casing head, such as a flow T '8, provided with the usual'oil-saver 9, and a flow connection H] in which is mounted a valve H.

A by-pass pipe l2 fitted with a valve it, provides communication'between the annular space v between lubricator 5 and casing .l and the interior The lubricator proper comprises the elongated tubular chamberB which is of a length sufficient to, accommodate strings of tools of any desir able length and itse'xternal diameter is sufii- 4 ciently less than the internal diameter of casing so that the annular space thus provided will be wide enough to accommodate and allow free movement of the valve operating mechanism-to be described'below. Chamber '5 is threaded at its upper 'endto 'engagea collar M positioned in cover plate fi and at one side of the center thereof. Nipple 1 screws into the upper end of collar [.2 from above cover plate 6. The lowerend .ofchamber 5 extends into the upper end of a tubular valve cage l5 fixedly attached thereto, the end face of chamber 5 forming an annular valve seat IS. The lower end of valve cage I5 is provided with a guide shoe I! and its upper end has a pair of spaced laterally extending hinge plates |8|8. A full opening type of valve such as disk valve I9, is provided with a tongue 20 which extends between hinge plates |8-||l and is fixedly attached to a shaft 2| which is journalled in hinge plates |8|8. Turning of shaft 2| causes disk valve I9 to swing relative to valve seat |6 for opening and closing the valve. An opening 22 is cut in the side of valve cage I5 to allow the valve l9 to swing down and outwardly from seat I6 to provide full clearance through the valve cage so that movement of tools therethrough will be unobstructed. A bumper 23 extendingfrom the upper edge of shoe limits the outward movement of disk valve IS; The ends of shaft 21 extend through hinge plates [8-48 and are connected to horizontal arms 24-24 positioned at opposite sides of valve cage l5 and hingedly connected to the lower ends of a pair of vertically extending links 2525, the upper ends of which are hingedly connected to the ends of an arcuate yoke 26 which extends around the side wall of chamber 5 above the hinge plates |8 |8. An elongated valve stem 21 is rigidly attached to the center of yoke 26 and extends upwardly along the side of chamber 5 to the valve operating mechanism located on top of cover plate 6. Valve stem 21 is held in position alongside chamber 5 within the annular space between chamber 5 and casing I by means of a plurality of vertically spaced loops 28-28. and 29 which are rigidly attached to the side wall of chamber 5.

The guide loops 28-28 are so positioned with respect to the lower end of the valve stem 21 as to act as stops limiting the extent of vertical 1 movement of yoke 26 therebetween and thereby limiting the swing of disk valve IS in response to reciprocation of valve stem 21,

Valve stem 21 extends upwardly along the side of chamber 5 through cover plate 6, passing through a stufing box 3|] on top thereof. A lever 3| having hinged attachment at 32 to an upright 33 extending. from cover plate 6 and hinged thereto at 33a, is pivotally attached at an intermediate point at 34 to a clevis 35 mounted on the upper end of valve stem H. A U-shaped lock member 36 is positioned on top of cover plate 6 between upright 33 and stuffing box 3|], being hingedly attached at its lower end at 31 to the top of cover plate 5 and vertically adjustable relative thereto by means of a threaded connection 36a, Lever 3| moves up and down in look member 35 to effect corresponding movements of the valve stem 21 when operating disk valve I9. Lock member 36 is provided with vertically spaced openings 3838 adapted to register with a corresponding opening in lever 3| for the insertion of a locking bolt 39 in order to fix lever 3| in look member 36 in a position correspondingto the open or closed position, as. desired, of the valve at the bottom of the lubricator. As will be evident from Fig. 6 the collar M which provides connection between chamber 5 and nipple is located somewhat off-center of cover plate 6,

providing room for locating the valve control mechanism on top of the cover plate in registering relationship to valve stem 21 which is, of course, located at one side of the longitudinal axis of casing In operation the described lubricator is employed in the following manner. Assume the well is under pressure of gas coming from below and it is desired to insert a string of tools 4|) into the well for drilling, cleaning out, or for any other desired purpose. Valve l3 in by-pass I2 is closed and disk valve I9 moved to the closed position shown in full lines in Fig. 3, particularly. This shuts off the interior of the lubricator completely from the pressure within the well. Any pressure within the lubricator, due to its having previously been in open communication with the well, is released through flow connection ID to the usual flow tank or pit, not shown, by opening valve The oil saver 9 is then removed from the top of casing head 8 and the string of tools 40 suspended from the usual wire cable is inserted into the body of the lubricator through the open top of casing head 8. When the tools are inside the lubricator, the oil saver is replaced, enclosing the cable and sealing same against escape of pressure fluid from the Well. Valve II is closed and valve l2 opened, allowing the pressure fluid in casing to enter the interior of the lubricator through nipple and equalize the pressure inside the lubricator .With that in the casing. Disk valve I9 may now be opened by suitable manipulation of valve stem 21 by means of lever 3| as shown in dotted outline in Figs. 2 and 3, and the string of tools 40 may now be dropped through the open lower end of the lubricator into the well and operated therein in performance of any desired operations without any hindrance by virtue of any pressure existent in casing I, and under perfectly safe control. Valve may now be opened and the drilling or other operations may be carried on 'while the well fluids are permitted to flow through connection ID to storage or waste as desired.

When it is desired to remove the tools from the well, they are drawn up into chamber 5 and disk valve l9 moved to the closed position against seat l6. Valve |3 is closed and the interior of the lubricator is thus shut off from the pressure in the well. Valve II is opened, if not already open, to relieve any pressure from the interior of the lubricator, oil saver 9 removed, and the tools withdrawn from the well. The oil saver is then replaced and if it is desired to flow the well, the lubricator valve and valve I are opened and the well permitted to flow through the lubricator.

From the foregoing, it will be evident that the device of this invention provides a safe, simple, and permanent structure for moving tools in and out of a well under pressure, without hindrance to the work by flow of fluids from the well, and one which is adaptable for use with tool strings of any desired length, which requires no lengthy and diflicult rigging-up and tearing-down operations, and which is free of the hazards attending the use of more conventional devices in use heretofore.

The lubricator of this invention is restricted in size only to such as will be readily insertible in a well casing leaving suficient annular space between the lubricator and well casing for free movement of the valve operating mechanism. A difference in diameter of about 3 inches ordinarily is ample to accommodate such mechanism. Any suitable length of lubricator may be used.

Numerous modifications and alterations may be made in the size, form, and arrangement of the details of this invention without departing from the scope of the appended claims.

What I claim and desire to secure by Letters Patent is:

1. A casing-head structure comprising a tubular body having a central bore therethrough and arranged to be inserted inside a well casing, valve means adapted to open and close the lower end of said bore, a fluid tight connection between said body and said casing, a closure for the top of said bore, pressure equalizing means connecting said central bore with the interior of said casing, and means for operating said valve means.

2. A casing-head structure comprising a tubular body having a central bore therethrough and arranged to be inserted in a well casing, valve means at the lower end of said body to open and close said bore, a fluid tight connection between said body and said casing, a closure for the top of said bore, pressure equalizing means connecting said bore with the interior of said casing and means operable from outside said casing for operating said valve means.

3. A casing-head structure comprising a tubular body having a central bore therethrough and arranged to be inserted inside the upper end of a well casing, a fluid tight connection between the upper end of said body and the top of said casing, a valve positioned at the lower end of said body and adapted to open and close said bore, a closure for the upper end of said bore, pressure equalizing means connecting said bore with the interior of said casing, and valve operating means extending from said valve through said fluid tight connection to the outside of said structure.

4. A casing-head structure comprising a tubular body having a. central bore therethrough and arranged to be inserted inside the upper end of a well casing, said body being of smaller diameter than said casing providing an annular space ,therebetween, a fluid tight connection between said body and said casing, a valve positioned at the lower end of said body and adapted to open and close said bore, a hollow closure member for the upper end of said bore positioned above said connection, a valved by-pass conduit around said connection providing communication between said annular space and said central bore through said hollow closure member, and valve operating means extending from said valve through said annular space and said fluid tight connection to the exterior of the structure.

5. A well lubricator comprising in combination with a well casing, an elongated tubular body having a central bore therethrough inserted inside the upper end portion of said casing, said tubular body being of smaller diameter than said casing to provide an annular space therebetween, a fluid tight connection between the upper end of said body and the top of said casing, a tubular valve casing arranged about the lower end of said body, an annular valve seat in said valve casing formed by the lower end of said body, a valve closure hing'edly mounted in said valve casing and cooperating with said seat, means for moving said closure relative to said valve seat including a valve stem member extending longitudinally of said body through said annular space and said fluid tight connection to the exterior of said casing, a hollow closure member for the upper end of said body positioned above said fluid tight connection, and a pressure equalizing pipe providing communication between said annular space and said central bore.

HUGH F. CYPHER. 

